Method for controlling an articulated turntable ladder of a rescue vehicle

Abstract

The present invention relates to a method for controlling an articulated turntable ladder ( 12 ) of a rescue vehicle ( 10 ) wherein the ladder ( 12 ) comprises a plurality of telescopically extendable ladder parts ( 14 ) by including a tip ladder part ( 18 ) pivotable around a horizontal first pivot axis ( 28 ) by means of a first pivoting drive. The ladder further comprises a cage ( 22 ) connected to the free end of the tip ladder part ( 18 ) to be pivoted around a second pivot axis ( 30 ) by means of a second pivoting drive. The ladder ( 12 ) is pivotably mounted to a base part ( 16 ) on top of the vehicle ( 10 ) by means of a third pivoting drive to be lifted or lowered around a third pivot axis ( 32 ). The method provides for the step of controlling the first pivoting drive such that the absolute inclination angle (α) of the tip ladder part ( 18 ) is maintained constant during a lifting or lowering movement of the ladder ( 12 ) around the third pivot axis ( 32 ).

The invention claimed is: 
     
       1. A method for controlling an articulated turntable ladder of a rescue vehicle, said ladder comprising a plurality of telescopically extendable ladder parts including a tip ladder part that is connected to one or more other ladder parts of the plurality of telescopically extendable ladder parts to be pivoted around a horizontal first pivot axis by means of a first pivoting drive, a cage being connected to a free end of the tip ladder part to be pivoted around a second pivot axis by means of a second pivoting drive, said ladder being pivotably mounted to a base part on top of the vehicle by means of a third pivoting drive to be lifted or lowered around a third pivot axis, said second pivot axis and said third pivot axis being parallel to said first pivot axis, the method comprising:
 controlling the first pivoting drive such that an absolute inclination angle of the tip ladder part is maintained constant during a lifting or lowering movement of the ladder around the third pivot axis, the absolute inclination angle of the tip ladder part being selected from a set of predetermined absolute inclination angles upon a user input command. 
 
     
     
       2. The method according to  claim 1 , further comprising controlling the second pivoting drive such that an absolute orientation of the cage is maintained constant during a lifting or lowering movement of the ladder around the third pivot axis. 
     
     
       3. The method according to  claim 1 , characterized in that the plurality of different absolute inclination angles comprises at least one of a maximum downward inclination angle of the tip ladder part, a maximum elevation angle of the tip ladder part, and a horizontal angle in which the tip ladder part is held in a horizontal position. 
     
     
       4. The method according to  claim 1 , characterized in that upon generation of a lifting or lowering command, the ladder is lifted or lowered by operating the third pivoting drive in a first direction, while the first pivoting drive is operated in a second direction opposite to the first direction. 
     
     
       5. The method according to  claim 1 , characterized in that a position of the tip ladder part is monitored by means of sensors. 
     
     
       6. The method according to  claim 1 , characterized in that at the end of a lifting or lowering movement of the ladder around the third pivot axis, an absolute position of the tip ladder part and/or the cage is adjusted. 
     
     
       7. A method for controlling an articulated turntable ladder of a rescue vehicle, said ladder comprising a plurality of telescopically extendable ladder parts including a tip ladder part that is connected to one or more other ladder parts of the plurality of telescopically extendable ladder parts to be pivoted around a horizontal first pivot axis by means of a first pivoting drive, a cage being connected to a free end of the tip ladder part to be pivoted around a second pivot axis by means of a second pivoting drive, said ladder being pivotably mounted to a base part on top of the vehicle by means of a third pivoting drive to be lifted or lowered around a third pivot axis, said second pivot axis and said third pivot axis being parallel to said first pivot axis, the method comprising:
 controlling the first pivoting drive such that an absolute inclination angle of the tip ladder part is maintained constant during a lifting or lowering movement of the ladder around the third pivot axis; and 
 controlling the second pivoting drive such that an absolute orientation of the cage is maintained constant during a lifting or lowering movement of the ladder around the third pivot axis; 
 wherein the absolute inclination angle of the tip ladder part is selected from a set of predetermined absolute inclination angles upon a user input command.